The inspiration for this robot is of course
Steve Hassenplug's Legway,
the world-famous self-balancing LEGO robot. The control program
is much more rudimentary than Steve's, but is sufficient for
NXTway to keep balanced for a while...

February
2007 update: Ryo Watanabe made an outstanding version
of NXTway using a gyro sensor. Have a look to his very well
documented realization: NXTway-G.

ProgramThe control program was written usingand BricxCC.
You can get NXTway source program here.
You may need to modify some parameters to adapt to the sensibility
of your light sensor, especially the "scale" parameter.

If you can't or won't compile the program, here
is the executable version.
It must be sent to your NXT using the download button
of the NXT program panel. As said above, this program
is adapted to my light sensor and may not work well
with yours.

ConstructionNo
building instructions (yet) but it should be easy to build NXTway
from photos below.

Light sensor assembly

Motor assembly.

UsageIn
its present state, NXTway is picky on environmental conditions:

The lighting must not interfere with light sensor. Try
your NXT in a dark room, or a room lit only by fluorescent
light (fluorescent lamps emits little or no infra-red light
so the light sensor is almost insensitive to their light).

It works best on a clear but non uniform surface. Some
patterns give NXTway something to "zero" on.

When you press the run button, NXTway must be perfectly
balanced, as light level measured at that time determines
the equilibrium position.